A prior art search of the present invention reported sixteen patents of which the following were most germane:
1,867,187-Soule et al,
3,150,884-Drott et al,
3,410,008-Standfuss,
3,659,362-Bell, and
3,987,562-Deen et al.
Standfuss is perhaps most relevant but it will be noted that his guide/coupling mechanism is semipermanently affixed to the frame of the vehicle by bolts and the range for vertical and horizontal guidance is limited.